A first aspect of wind turbines relates to electric power efficiency of the converter system. Even a small improvement of the power efficiency may be significant for the profitability of the investment in wind turbines due to increased power production.
A second aspect of wind turbines relates to the reliability of the converter system. Improved reliability of the converter system increases the reliability of the wind turbine, thus increasing the mean-time-between-failure (MTBF) of the wind turbine. The increase of the mean-time-between-failure consequently decreases service costs and increases the power production over time, which is important for the profitability of the investment in wind turbines.
WO 2004/030189 discloses power conversion units (PCU's) adapted to convert power from the first form to other forms suitable for use by the components of the destinations system. The power sources can include a variety of power generating devices, such as a wind turbine. The power, after having been converted, is supplied to one or more variable loads of the destination system. These variable loads can represent the power requirement from the operation of a motor, a servo, an electric circuit and the like. The operation of the system may include activating/deactivating one or more of the PCU's in response to an increase/decrease in the consumption of power by the destination system. By deactivating a PCU during periods of lower power consumption, an improvement of the overall efficiency of the power distribution system is obtained. However, WO 2004/030189 neither considers how to improve the mean-time-between-failure of the power conversion units, nor does it consider how to manage changes in the produced amount of electric power being inputted to PCU's, and thus, WO 2004/030189 does not consider how to improve the efficiency of the PCU's in a system wherein the amount of power being input to the PCU's is not constant over time.